An electric bulb A. 100 W

B. 75 W

C. 50 W

D. 25 W

The bulb parameters are as given below:

Power, P = 100W

Potential difference, V = 220V

Then Resistance, R = ?

Now,

This resistance of the bulb will remain constant i.e. 484

Now, when we operate this bulb on 110 V, then,

Power, P =?

Potential difference, V = 110V

And, resistance, R = 484

P =

P = = = 25 W

Thus, the correct answer is: (d) 25 W.